Reinforced soil bridge

ABSTRACT

The structure of the invention is particularly useful in building reinforced soil arch bridges having relatively long transverse axial spans in the range of 30 feet or more. Structure includes a substantially cylindrical liner of relatively thin wall corrugated metal sheet. The structure is characterized by the provision of one or more open-top bins disposed along the upper surface of the liner. Earth-fill is compacted in layers in the bins and around the liner. The bins serve to confine and thus reinforce and strengthen the compacted earth-fill so that a reinforced soil bridge is formed. The bins also serve as stiffeners for the liner.

United StatesPatent [191 [111 3,73,59 Watkins 5] May 29, 1973 REINFORCEDSOIL BRIDGE [75] Inventor: Reynold K. Watkins, Logan,.Utah Primary 'f fwilliamowsky Assistant Exammer-Phil1p C. Kannan [73] Asslgnee: UnitedStates Steel Corporation, An0rney DOna1d S Ferito Pittsburgh, Pa.

221 Filed: Oct. 29, 1971 [571 ABSTRACT [21] APPL No; 193,727 Thestructure of the invention is particularly useful in bulldlng relnforcedSOll arch brldges having relatively long transverse axial spans in therange of 30 feet or [52] US. Cl ..6l/16 more Structure includes asubstantially Cylindrical 51 Int. cl ..F16l9/04 liner of relatively thinwan corrugated metal sheet [58] Field of Search ..61/l6, 39, 15 14, TheStructure i characterized by the provision of one 61/10 35; 94/33 ormore open-top bins disposed along the upper sur face of the liner.Earth-fill is compacted in layers in [56] References c'ied the bins andaround the liner. The bins serve to con- UNITED STATES PATENTS fine andthus reinforce and strengthen the compacted Y Y Y earth-fill so that arelnforced soll bridge is formed. 3,508,406 4/1970 Fishers". ..61 16 Thebins also serve as stiffeners for the liner.

701,034 5/1902 Gray 4/]935 Carswell et al. ..6l/l6 7 Claims, 4 DrawingFigures REINFORCED SOIL BRIDGE BACKGROUND OF THE INVENTION As is wellknown, corrugated culvert construction results in an arch-type bridgecomprising two individually weak elements, a relativelythingalvanizedcorrugated steel liner, and an archof compacted soil over theliner. Although the liner and the arch'of compacted soil are eachindividually weak, the combination of the two I as the amount of steelused in the construction increases or if anexcessive amount of concreteis needed to provide abutments or buttresses. The thickness of the steelliner is, therefore, an important consideration and must be held to aminimum commensurate with the length of span and depth of soil cover.Prior to my invention these considerations for the most part limited thestructure of culvert bridges to those having a length of transverseaxial span less than 30 feet. Certain types of structures have beensuggested for providing long span culvert bridges; however, none ofthese have been entirely satisfactory for economic or other reasons. Onesuch type of culvert construction is taught by U.S. Pat. No. 3,508,406.Other U.S. Pats. relating to archtype bridge construction are thefollowing: Nos. 597,590 to Pratt, 1,926,843 to Fischer, 1,964,313 toCarswell et al., 1,999,500 to Carswell et al., 2,056,349 to Evers,2,126,091 to Claybaugh, 2,126,870 to Carswell et al., 2,536,759 toMartin et al., 2,718,117 to Boyle et al., 3,282,056 to Fisher, and3,495,410 to Bailey et al.

It is, accordingly, the primary object of my invention to provide animproved reinforced soil arch bridge construction which is economicaland makes possible the construction of reinforced soil bridges havinglonger transverse axial spans than was heretofore possible.

It is a more specific object of my invention to provide a reinforcedsoil bridge structure of the type set forth in the object stated abovewhich includes a relatively thin wall substantially cylindrical metalliner and one or more open-top bins which are disposed along the lengthof the upper surface of the liner. Well compacted earth-fill consistingof sand and/or gravel surrounds the liner and fills the bins.

These and other objects will become more apparent after referring to thefollowing specification and attached drawing, in which:

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a substantially schematicview in perspective and partly in section showing a preferred embodimentof my invention;

1 FIG. 2 is similar to FIG. 1 but showing a modified embodiment of myinvention;

FIG. 3 is similar to FIG. 1 but showing still another modifiedembodiment of my invention; and

FIG. 4 is similar to FIG. 1 but showing yet another modified embodimentof my invention.

DESCRIPTION OF TI-IEPREFERRED EMBODIMENTS Referring more particularlyfor the time being to FIG. 1 of the drawing, reference numeral 2designates the liner of the bridge of the invention. The liner iscomprised of a number of heavy gage sheets or thin plates"(approximately 0.1084 to 0.50 inches thick) bolted together atoverlapping points (not shown) into substantially cylindrical shape. Theindividual sheets or plates are shop-fabricated, i.e., corrugated,shaped and galvanized in the shop, and then subsequently assembled intothe substantially cylindrical shaped'liner at the site. The assembledliner serves as a form for earthfill 4, which is preferably sand and/orgravel, placed in layers on both sides of the liner with the individuallayers being tightly compacted by rolling, vibrating, or other suitablemeans. The progressive compacting of soil against the liner 2 stiffensthe latter.

Fin elements 6, which may be steel sheets or plates, or other suitablematerial, corrugated or flat, are provided attached to, by welding orother means, projecting from the exterior of the liner 2-extendinglongitudinally thereof. The fin, element 6 may project from the exteriorof the liner 2 at any angle, as desired.

A plurality of substantially triangular shaped plates 8 are spaced alongthe length of each of the fin elements 6 with each plate being disposedwith its 'base attached upright and edgewise to the inner surface of itsrespective fin element 6. Each plate 8 is attached to the exterior ofthe liner 2. The plates 8 may be attached to the fins 6 and to theexterior of the liner 2 by welding or other suitable means. Thetriangular plates 8 attached to one fin element 6 extend toward theopposite fin element. The plates act to stiffen-the liner 2 and togetherwith the fin elements 6 form bins 10. The bins 10 are filled with thecompacted earth-fill 4. The bins 10 confine the soil over the linerthereby increasing the soils shearing strength such that wedgesor'slices thereof cannot slip down.

If desired, the fin element 6 may be discontinuous, as shown in FIG. 2.For purposes of obtaining positive drainage, the fin element 6 may bedisposed, detached from and not abutting the liner 2 as shown in FIG. 3.In this arrangement the triangular plates 8 are attached to the outersurface of the liner.

FIG. 4 shows an embodiment of the invention wherein only one bin 10 isprovided on the liner 2. This arrangement has particular utilization inthe construction of relatively narrow soil bridges, such as pedestriancrossovers.

In each of the embodiments shown in FIGS. 1, 2, 3 and 4, the opposingtriangular plates 8 may be joined at their apices to form continuouselements extendin from one fin to the opposite fin.

If desired, the assemblies consisting of the bins 10, the triangularshaped plates 8 and the fin elements 6 may be positioned loosely on theliner while the earthfill is compacted therein and therearound.

It will be noted that although I have shown the liner 2 as asubstantially continuous cylinder, it may be another cylindrical form,such as an arch supported on footings.

It will be obvious that the arrangement of my invention provides areinforced soil bridge wherein the soils shearing strength is increasedto an'amount not possible heretofore so that wedges or slices thereofcannot slip down and weaken the soil bridge.

While I have shown but four embodiments of my invention, otheradaptations and modifications may be made without departing from thescope of the following claims.

I claim:

1. A reinforced soil arch bridge comprising a metal liner having anupper portion, an open-top bin on said liner, said bin having opposedside and end walls projecting upwardly of said liner to a substantiallycommon horizontal plane above the upper portion of said liner, andcompacted earth-fill contained in said bin and surrounding said liner.

2. A reinforced soil arch bridge comprising a metal liner having anupper portion, a plurality of open-top bins disposed along said liner,each of said open-top bins having opposed side and end walls projectingupwardly of said liner to a substantially common horizontal plane abovethe upper portion of said liner, and compacted earth-fill contained insaid bins and sur rounding said liner.

3. A bridge as defined by claim 2 in which said bins are spaced apartalong said liner.

4. A reinforced soil arch bridge comprising a longitudinally elongatedmetal liner, a plurality of open-top bins spaced longitudinally alongsaid liner, said plurality of bins being formed of a pair of spaced finelements projecting from but not abutting or attached to the exterior ofsaid liner, a plurality of substantially triangular shaped plates spacedalong the length of each of said fin elements, each of said triangularplates being disposed with its base attached upright and edgewise to theinner surface of its respective fin element and one edge thereofconforming with and attached to the exterior of said liner, thetriangular plates attached to one fin element extending toward thetriangular plates attached to the other of said fin elements, andcompacted earth-fill contained in said bins and surrounding said liner.

5. A bridge as defined by claim 4 in which said fin elements are inabutment with and attached to the exterior of said liner.

6. A bridge as defined by claim 4 in which said fin elements arediscontinuous forming separate sections and a pair of spaced triangularplates is attached to each of said fin element sections thereby formingspaced apart bins along said liner.

7. A bridge as defined by claim 6 in which said fin elements are inabutment with and attached to the exterior of said liner.

1. A reinforced soil arch bridge comprising a metal liner having anupper portion, an open-top bin on said liner, said bin having opposedside and end walls projecting upwardly of said liner to a substantiallycommon horizontal plane above the upper portion of said liner, andcompacted earth-fill contained in said bin and surrounding said liner.2. A reinforced soil arch bridge comprising a metal liner having anupper portion, a plurality of open-top bins disposed along said liner,each of said open-top bins having opposed side and end walls projectingupwardly of said liner to a substantially common horizontal plane abovethe upper portion of said liner, and compacted earth-fill contained insaid bins and surrounding said liner.
 3. A bridge as defined by claim 2in which said bins are spaced apart along said liner.
 4. A reinforcedsoil arch bridge comprising a longitudinally elongated metal liner, aplurality of open-top bins spaced longitudinally along said liner, saidplurality of bins being formed of a pair of spaced fin elementsprojecting from but not abutting or attached to the exterior of saidliner, a plurality of substantially triangular shaped plates spacedalong the length of each of said fin elements, each of said triangularplates being disposed with its base attached upright and edgewise to theinner surface of its respective fin element and one edge thereofconforming with and attached to the exterior of said liner, thetriangular plates attached to one fin element extending toward thetriangular plates attached to the other of said fin elements, andcompacted earth-fill contained in said bins and surrounding said liner.5. A bridge as defined by claim 4 in which said fin elements are inabutment with and attached to the exterior of said liner.
 6. A bridge asdefined by claim 4 in which said fin elements are discontinuous formingseparate sections and a pair of spaced triangular plates is attached toeach of said fin element sections thereby forming spaced apart binsalong said liner.
 7. A bridge as defined by claim 6 in which said finelements are in abutment with and attached to the exterior of saidliner.